The proposed research attempts to achieve a comprehensive understanding of the cognitive social psychological factors in adolescent cigarette smoking. In a longitudinal study, we will examine the psychological processes underlying the important period of transition from nonsmoker to smoker. Two major social psychological theories (Ajzen and Fishbein's model for the prediction of behavioral intentions and Jessor and Jessor's Problem Behavior Theory) will be used to predict such transitions. We will also identify "high risk" variables for smoking transitions by comparing the presmoking data for subjects who begin to sm ke over the course of the study with the data for subjects who do not begin to smoke. Furthermore, by examining "high risk" adolescents who do not begin to smoke, we can identify variables that serve as deterrents to smoking. We will examine adolescents' belief systems to determine which types of attitudes and beliefs are most relevant to smoking decisions. In addition, we hope to specify factors which determine the weights of the various components in the prediction of adolescent smoking. Using our longitudinal design, changes in the attitudes and beliefs can be related to changes in smoking status so that the mutual influence of cognitions on behavior and of behavior on cognitions can be studied. Several cross-sectional studies are proposed which supplement the major longitudinal approach. For example, using several measures, we will study characteristics that are attributed to smoking in a variety of contexts. Evaluations of smokers and nonsmokers in these contexts should help us discover some of the functions that sm king serves for adolescents. The focus of the current proposal is the onset of smoking in adolescence. The results will have direct applications to guide the content of antismoking programs as well as to identify the most appropriate target groups for such campaigns. The proposal includes a first step towards this goal. We will investigate the differential effectiveness of different antismoking messages aimed at distinct subgroups of adolescents.